Shank stiffener with attaching means



Feb. 5, I935. s. M. NICKERSON 1,990,247

SHANK STIFFENER WITH ATTACHING MEANS Filed March 7, 1954 Patented Feb.5, 1935 SHANK STIFFENER WITH ATTACHING' MEANS Stacy M. Nickerson,Newton, Mass Dplication"March 7, 1934, Serial No. 714,470

38 Claims. (01. 36-76) The present invention relates to the metal shankstifieners which are used in shoes for the purpose of maintaining theshape of the shank part of the shoe. It is particularly concerned withmeans for anchoring or attaching the stiffener to the innersole, for thepurpose of holding it permanently in place; not. only during themanufacture of the shoe, but afterwards when the shoe. is on the wearersfoot and subjected to flexure of various directions by the weight andmovements of the wearer.

I-Ieretofore it has been the practice to secure such shank stiffeners bymeans either of separate tacks or of integral prongs cut from thesubstance of the stiffener itself driven through the innersole andclinched at the inner side of thelatter. Such tacks and prongs havealways heretofore been made with sharp points and clinching of theirpointed ends has been essential to prevent their withdrawal. Buttoclinch them requires that they be made longer than the thickness ofthenormal innersole, and that the last on which the shoe is made benon-penetrable by the points of the prongs. Practically this has limitedthe use of permanent attaching means for shank stiffeners to shoes madeon lasts which either have a continuous iron or steel plate on thebottom, or such a plate on the heel part. Where the heel part only ofthe last'is thus armored, the shank stiffener can be secured by clinchedpoints only at the heel end thereof, which leaves the forward end freeto rub and make squeaking noises when the shoe is worn, and to shiftside- 'wise out of place.

The cost of equipping lasts with complete bottom plates of iron or steelis so great as to be practically prohibitive, particularly when stylesare changed so frequently that the factories have to be equipped withnewlasts at frequent intervals. Some shoe manufacturers have sought tolessen this expense by providing a bottom plate only at the heel partand setting an iron insert into the last bottom at the ball partthereof, which is the location of the forward end of the shankstiffener, so as to provide a clinching anvil for prongs or the like atsuch forward end. But this practice also is too expensive to besatisfactory. Consequently the more general usage at the present time isto stick the shank stiffeners to the innersole with cement only. Thismode of attachment is effective only to retain the stiffener during theshoe making process, and is wholly ineffective to prevent it fromshifting out of place throughout the wearing life of the shoe,

Another fatal objection to integral clincher prongs on shank stiffenersis the quality of the steel from which a large proportion of the shanksnow in use are made. In order to provide adequate strength andresilience, these shank stiffeners are made of a hard steel composition;so hard that sharp prongs formed from their substance usually break whenthe attempt is madeto clinch them. When broken, the remnants of suchprongs, due

to their inclined side edges, quickly work out of the innersole when theshoe is-being worn, and allow the stiffener to shift out of place. e Iheinvention herein consists in a shank stiffener having attaching meanswhich are free from the objections above referred to, and are effectiveto secure the stiffenerin place without penetrating through the entirethickness of an innersole and without being clinched.

The drawing furnished herewith depicts the invention in a variety ofequivalent-embodiments.

Fig. 1 shows a perspective View of my new shank stiffener equipped withintegral anchor lugs at opposite sides adjacent to its two ends;

. Figs. 2 and 3 are detail sectional views on lines 2-2 and 3-3respectively of Fig. 1;

Fig. 4 is an elevation of a shoe, with the shank part represented insection and showing the shank stiffener of Fig. 1 incorporated therein;

Figs. 5, 6 and 7 are views similar to Fig. 1 showing specificallydifferent variants of the same invention;

Fig. 8 is a cross section on line 8.-8 of Fig. '7.

Like reference characters designate the same parts wherever they occurin all the figures.

or represents the shank stiffener body. This may be of any suitable formand dimensions, and is shown here as made from a strip of sheet steelapproximately A in width, strengthened by being offset along its medianline except at the ends, and being longitudinally curved conformably tothe shank part of the shoe for which it is designed. The inventioncomprehends nothing newin these particulars, but may be embodied inshank stiffeners of widely varying character istics. The new step isembodied in the attach ing means, which in Figs. 1 and 2 consist ofanchor lugs b, b' a'djacent to one side edge of the stiffener body, nearthe opposite ends thereof; and similar anchor lugs c, 0' near. therespectively opposite sides and ends of the body. These-lugs are formedby incising the shank body inwardly from its edge, on linesperpendicular to the edge, and bending the substance 9f the .Shank bodybetween such cuts; up at right trated in Fig. 4. Shankstifienersequipped; with angles to the plane of the adjacent part of the body. Byvirtue of this construction, the lugs have parallel sidestheir endbounding edges are perpendicular to these sides, and they have the samethickness as the stock of which the shank leather-board, fiber, or othersuitable material. But they are made of a height less than the thicknessof the normal innersole stock so that, when the stiffener is appliedto'an innersole (1 (Fig.4) attached to the bottom of a last, the-- lugswill enter the substance of the innersole, but will not pass through it,substantially as illusthese attaching means are laid against the outerface of the innersole attached to a last bottom, as,usual, and theanchor lugs are driven into the innersole substance by hammer blows ateach end of the stiffener. v, Y

' An adequately strong bond is created between the embedded lug andtheinnersole material, notwithstanding that the lug is not clinched anddoes not pass all theway through the innersole. I attribute, thestrength of this bond to the fact that the sides of 'the lugs arestraight and paralleland their embedded corners are square, whereby theinnersole material tends to hug and grip'the lug, rather than to crowdit outward. Another factor which I believe contributes to this effect isthat the lugs have substantial width. Inthe example illustrated, theirwidth is approximately one tenth of an inch; but it is to be understoodthat I do not limit my protection narrowly in this particular. In termsof proportional dimensions, the ratio of protruding height of the lugshere illustrated to their'width is approximately as six or seven to ten;and of thickness to width, as four to ten. But'whatever the correctexplanation maybe, the demonstrated loose.

The anchor lugs aslshown in this drawing and heretofore described, haveequal width at the extremity and base; (by base I mean the part of thelug which is connected with the body of the shank'stiffener). ;This isdue to the parallelism of the cuts which sever the sides of the lug fromthe body of the stiffener; Its corners are. square, due to the fact thatthe cuts extend perpendicular to the edge of the body. However, it iswithin my contemplation to make the lugs slightly wider at the extremitythan at the base, and make their corners slightly acute rather thansquare, in order to increase the strength of connection with theinnersole by providing: space into which the innersole substancemay'crow behind the entering edge of the lug.

Lugs such as those described above 'rnaybe variedin numbers andvariously positioned; but preferably they are always near the oppositeends ,of the-stiffener where they leave the middle part free to flexunder the weight of the wearer. Fig.

.lugs -b and c of Fig. 1; i. e., at respectively opposite sides andoppositeends of the stiffener.

Fig. 6 shows'a variation in which there are two such lugs, e'and 6,located respectively at the extreme ends of the stiffener body withtheir width' dimensions extending crosswise of the body,

instead of longitudinally as in the other forms illustrated. a

Fig. 7 shows a further variation in whichthere are lugs corresponding toc and c of Fig. 1 for embedding into the innersole, and other lugs f andf, of similar formation but oppositely turned, to be embedded in theouter sole as an additional anchorage against shifting of the stiffenerin the completed shoe while being worn.

It will be understood that outturned lugs corresponding to f and i maybe located at any desired points along the sides or ends of thestiffener body, and provided in any desired numbers,,in connection withupturned lugs arranged as shown in Figs. 5 and 6, or otherwise.

Such lugs may be formed in shank stiflfenersv of hard steelcompositions, being severed and bent up before the stiffener bodies arehardened and tempered; That is, they are serviceable with sti-ffeners ofthose compositions which, in clincher forms, would causebreakage oftheprongs when clinched. They are, equally serviceable inconnection withall types of lasts, ,wh'ether'the latter are entirely of wood, or, haveiron bottoms; and as they cannot penetrate, to the inside of the shoe,they cause neither discomfort to the wearer nor destruction of thewearers stocking. v

What I claim and desire to secure by Letters Patent is: 1. A shankstiffener. of metal having an integral upturned anchor lug of a. lengthless than sufhcient topenetrate'throughia normal innersole, and of awidth at its extremity substantially as great as its base width. 2. Ashank stiffener of metal. having an integral upturned'anchor lug. of,alength less than sufiicient .to penetrate through a normal innersole,and of a width at its extremity substantially as great as its basewidth, the end bounding edge of said lug being substantially straightand making substantially equal angles with both side bounding edges, I

3. A shank stiffener of metalhaving an integral, upturned anchor lug ofa length lessthan sufficient to penetrate through a normal innersole,and of a width at its extremity substantially as great asitsbasewidth,the outer cor ners of such lug being substantiallysquare. a 4. A shankstiffener ofstifi sheet metalhaving an integral lug formedasajpartiallysevered tongueprojecting substantially at right angles tothe portion of the stifiener body contiguous to its base and havingsubstantially parallel side edges substantially perpendiculari-to saidcon tiguous part of the .body.

5. A shank stiffener of tempered. steel having an integral upturnedanchor lug of which both outer corners are no greater than a right angleand the height is less than the thickness of a normal innersole, whilethe thickness is small enough to permit penetration into the substanceof an innersole. 1 1 r Y 6. A shank stiffener consisting of a bodyformed from sheet steel, hardened and tempered,

and having upstanding anchor lugs at opposite ly square end edge atsubstantially right angles -with such'sides; said lugs havingsubstantial width and being sufiiciently thin to penetrate innersolematerial; and the stiffener having similar lugs projecting oppositely tothe lugs first described adapted to be embedded in the substance of theouter sole of the shoe when the lugs first described are embedded in theinnersole of the same shoe.

'7. A shank stiffener consisting of a sheet steel body having integralanchor lugs partially severed from its substance and turned respectivelyupward and downward, adapted to be embedded in the material of theinnersole and outer sole respectively of a shoe; said lugs havingsubstantial width, with substantially square corners, and being of lessheight than the thickness of the innersole and outer sole respectivelyin which they are designed to be embedded.

8. A'shank stiffener consisting of a sheet steel body having integralanchor lugs partially sevouter sole in which they are designed to be em-10 bedded. STACY M. NICKERSON.

